title: Negative regulation of the actin-regulating kinase Prk1p by patch localization-induced autophosphorylation.
abstract: The Prk1 family of protein kinases are important regulators of endocytosis and actin cytoskeleton in some eukaryotic cells. In budding yeast, Prk1p phosphorylates numerous endocytic proteins including Pan1p and Sla1p. Prk1p has been observed to undergo autophosphorylation in vivo. In this study, we determined the sites and underlying role of the autophosphorylation. Two sites located in the noncatalytic region were identified to be the autophosphorylation sites. When the sites were mutated, the non-autophosphorylatable Prk1p phosphorylated Pan1p and Sla1p more efficiently than the wild-type kinase, suggesting a negative effect of the autophosphorylation. In addition, the dynamic properties of actin and the coat complex were also altered in the autophosphorylation mutant cells. Interestingly, the autophosphorylation of Prk1p was dependent on cortical localization of the kinase and could be induced by phosphorylated Sla1p. These results suggest that the autophosphorylation of Prk1p may represent a feedback mechanism possibly involved in fine-tuning the pace of progression during actin-coupled endocytosis.
authors.affiliation: Institute of Molecular and Cell Biology, 61 Biopolis Drive (Proteos), Singapore, Singapore.
authors.forename: Bo
authors.initials: B
authors.lastname: Huang
authors.forename: Ling Ling
authors.initials: LL
authors.lastname: Chua
authors.forename: Neeyor
authors.initials: N
authors.lastname: Bose
authors.forename: Mingjie
authors.initials: M
authors.lastname: Cai
mesh_terms: D000199:Actins / Q000378:metabolism*; D015536:Down-Regulation; D015966:Gene Expression Regulation, Fungal; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D010769:Phosphothreonine / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D000199:Actins; D029701:Saccharomyces cerevisiae Proteins; D010769:Phosphothreonine; C094326:PRK1 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases